VITRUM
VITRUM (
ὕαλος), glass. A
singular amount of ignorance and scepticism long prevailed with regard to
the knowledge possessed by the ancients in the art of glass-making. Some
asserted that it was to be regarded as exclusively a modern invention, while
others, unable altogether to resist the mass of evidence to the contrary,
contented themselves with believing that the substance was known only in its
coarsest and rudest form. It is now clearly demonstrated to have been in
common use at a very remote epoch. Various specimens still in existence
prove that the manufacture had in some branches reached a point of
perfection to which recent skill has not yet been able to attain; and
although we may not feel disposed to go so far as Winckelmann (1.100.2.20),
who contends that it was used more generally and for a greater variety of
purposes in the old world than among ourselves, yet when we examine the
numerous collections arranged in all great public museums, we must feel
convinced that it was employed as an ordinary material for all manner of
domestic utensils by the Egyptians, Greeks, and Romans.
A vitreous glaze is found in remains dating from the earliest periods of
Egyptian history, and we find the process of glass-blowing distinctly
represented in the paintings of Beni-Hassan, which were executed during the
reigns of Usertesen the First and his immediate successors (
circa 2300 B.C.). The oldest Egyptian glass proper
which can be dated with certainty is a vase of opaque blue glass in the
British Museum, with a design inlaid in yellow, which includes the name of
Thothmes II. (16th cent. B.C.). Vases also, wine-bottles, drinking-cups,
bugles, and a multitude of other objects have been discovered in sepulchres
and attached to mummies both in Upper and Lower Egypt; and although in most
cases no precise date can be affixed to these relics, many of them are
referred to an early period. (Wilkinson,
Ancient Egyptians,
iii.3 pp. 141 f.; Deville,
L'Art de la
Verrerie, pl. iii.)
The Assyrians also attained to a high degree of skill in glass-making. The
oldest piece with a fixed date is an alabastron of bright green glass from
the North-west Palace at Nimroud, with the name of king Sargon, B.C. 719
(Layard,
Nineveh and Babylon, p. 197; Froehner,
La
Verrerie ant. p. 16). This vase is in the British Museum.
A story has been preserved by Pliny (
Plin. Nat.
36.191), that glass was first discovered accidentally by some
merchants who having landed on the Syrian coast at the mouth of the river
Belus, and being unable to find stones to support their cooking-pots,
fetched for this purpose from their ship some of the lumps of nitre which
composed the cargo. This being fused by the heat of the fire, united with
the sand upon which it rested and formed a stream of vitrified matter. The
Phoenicians probably learnt the art of glass-making from the Egyptians; but
the tale is no doubt connected with the fact recorded by Strabo (
xvi. p.758) and Josephus (
B.
J. 2.9), that the sand of the district in question was esteemed
peculiarly suitable for glass-making, and exported in great quantities to
the workshops of Sidon, long the most famous in the ancient world. (See
Hamburger and Michaelis on the Glass of the Hebrews and Phoenicians,
Commentar. Soc. Gott. vol. iv.; Heeren,
Ideen, i. p. 94.) Alexandria, another centre of the industry,
sustained its reputation for many centuries; Rome derived thence a great
portion of its supplies, and as late as the reign of Aurelian we find the
manufacture still flourishing (
Cic. pro
Rabir. Post. 14, 40; Strabo,
l.c.; Martial,
11.11,
12.74,
14.115;
Vopisc.
Aurel. 45; Boudet,
Sur l'Art de la Verrerie
né en Egypte; Description de l'Egypte, vol. ix. p.
213).
Glass is not mentioned in Homer, unless Helbig's theory is accepted that
κύανος is a blue
[p. 2.973]vitreous glaze (Helbig,
Homerisches Epos, p.
80). In the deposits of Mycenae and kindred sites, numerous beads, rosettes,
pendants, and other ornaments of glass occur. Bottles, however, are very
rare; a few only having been found at Ialysos in Rhodes.
There is some difficulty in deciding by what Greek author glass is first
mentioned, because the term
ὕαλος, like
the Hebrew word used in the Book of Job (28.17) and translated in the LXX.
by
ὕαλος, unquestionably denotes not only
artificial glass but rock-crystal, or indeed any transparent stone or
stone-like substance (Schol.
ad
Aristoph. Cl. 768). Thus the
ὕελος of Herodotus (
3.24), in which the Ethiopians encased the bodies of their dead,
cannot be glass, although understood in this sense by Ctesias and Diodorus
(
3.15), for we are expressly told that it
was dug in abundance out of the earth; and hence commentators have
conjectured that rockcrystal or rock-salt, or amber, or Oriental alabaster,
or some bituminous or gummy product, might be indicated. But when the same
historian in his account of sacred crocodiles (2.69) states that they were
decorated with ear-rings made of melted stone (
ἀρτήματά τε λίθινα χυτὰ καὶ χρύσεα ἐς τὰ ὦτα
ἐνθέντες, we may safely conclude that he intends to describe
some vitreous ornament for which he knew no appropriate name. The
σφραγὶς ὑαλίνη and
σφραγῖδε ὑαλίνα of an Athenian inscription referred to
B.C. 398 (Boeckh,
Corp. Inscr. Gr. n. 150.50), together with
the passage in Aristophanes (
Aristoph. Ach.
74) where the envoy boasts that he had been drinking with the Great
King
ἐξ ὑαλίνων ἐκπωμάτων, are not
decisive. But the early Greek pastes with designs in intaglio, preserved in
all museums, make it highly probable that the seals referred to above were
of glass. Vessels of glass also appear to be mentioned in the treasure lists
at the beginning of the 4th century (
C. I. A. 2.645, 646,
656). Setting aside the two problems with regard to glass, attributed to
Aristotle, as confessedly spurious, we at length find a satisfactory
testimony in the works of his pupil and successor, Theophrastus, who notices
the circumstances alluded to above, of the fitness of the sand at the mouth
of the river Belus for the fabrication of glass. Blümner, however
(
Technologie, iv. p. 384), questions whether glass was
manufactured in Greece itself, even in the time of the Diadochi.
Among the Latin writers Lucretius appears to be the first in whom the word
vitrum occurs (4.604, 6.991); but it must
have been well known to his countrymen long before, for Cicero names it,
along with paper and linen, as a common article of merchandise brought from
Egypt (
pro Rab. Post. 14, 40). Glass of Phoenician
importation occurs indeed in cemeteries of the 8th century, at Tarquinii
(Helbig,
Homerisches Epos, p. 15). Scaurus, in his aedileship
(B.C. 58), made a display of it such as was never witnessed even in
after-times; for the
scena of his gorgeous
theatre was divided into three tiers, of which the under portion was of
marble, the upper of gilded wood, and the middle compartment of glass (
Plin. Nat. 36. § § 114, 189).
In the poets of the Augustan age it is constantly introduced, both directly
and in similes, and in such terms as to prove that it was an object with
which every one must be familiar (e. g.
Verg. G.
4.350,
Aen. 7.759; Ovid,
Amor. 1.6,
55;
Prop. 4.8,
37;
Hor. Carm. 3.13.1). Strabo declares
that in his day a small drinking-cup of glass might be purchased at Rome for
half an as (xvi. p. 758; compare Martial,
9.60),
and so common was it in the time of Juvenal and Martial, that old men and
women made a livelihood by bartering sulphur matches for broken fragments
(
Juv. 5.48; Martial,
1.42,
10.3; Stat.
Sylv. 1.6, 73; compare
D. C.
56.17). When Pliny wrote, manufactories had been established not only
in Italy, but in Spain and Gaul also, and glass drinking-cups had entirely
superseded those of gold and silver (
H. N. 36. §
§ 192-199), and in the reign of Alexander Severus we find
vitrearii ranked along with curriers, coachmakers,
goldsmiths, silversmiths, and other ordinary artificers whom the emperor
taxed to raise money for his thermae (Lamprid.
Alex. Sev.
24). A list of the glass-workers whose names are known as occurring on
extant specimens, is given by Froehner,
La Verrerie antique,
p. 123.
The numerous specimens transmitted to us prove that the ancients were well
acquainted with the art of imparting a great variety of colours to their
glass; they were probably less successful in their attempts to render it
perfectly pure and free from all colour, since we are told by Pliny that it
was considered most valuable in this state. It was wrought according to the
different methods now practised, being fashioned into the required shape by
the blowpipe; or
cut, as we term it, although
ground (
teritur) is a
more accurate phrase, upon a wheel; or engraved with a sharp tool, like
silver ( “aliud flatu figuratur, aliud torno teritur, aliud argenti
modo caelatur,”
Plin. Nat. 36.193). The
diatreta of Martial (
12.70) were glass cups cut or engraved according to one or other of
the above methods. The process was difficult, and accidents occurred so
frequently (
Mart. 14.115) that the jurists
found it necessary to define accurately the circumstances under which the
workman became liable for the value of the vessel destroyed (
Dig. 9,
2,
27,
29). The art of etching upon glass,
now so common, was entirely unknown, since it depends upon the properties of
fluoric acid, a chemical discovery of the last century.
We may now briefly enumerate the chief uses to which glass was applied. The
best idea, however, of the admirable ingenuity and skill of the ancient
glass-workers, may be obtained from such a collection as that of the British
Museum, or the chief continental cabinets. Specimens of the different types
are finely engraved by Froehner,
La Verrerie antique (1879).
1. Bottles, vases, cups, and cinerary urns. These specimens are extant in
immense number and variety. Many which have been shaped by the blowpipe
only, are remarkable for their graceful form and brilliant colours. Some
have been blown out into moulds, by the blow-pipe, and appear in the form of
a bunch of grapes (cf. Achilles Tatius, 2, 3), a shell, or a negro's head.
Others are of the most delicate and complicated workmanship. A very
remarkable object belonging to the last class, now in the Trivulsi
Collection at Milan, is described in the notes to Winckelmann (1.100.2.21)
and figured in Vol. I. under
DIATRETA That woodcut, however, hardly does justice to the
delicacy of the work, which is
[p. 2.974]better shown in the
photographic plate of Adda,
Ricerche sulle Artie sull' Industria
Romana. For a description, see
DIATRETA Vol. I., p. 626. A small fragment of a
similar vase may be seen in the glass collection of the British Museum.
Another cup, found at Strasburg, was dated by the name of the Emperor
Maximian (286-310. A.D.). This specimen, which perished in 1870, is engraved
by Deville,
L'Art de la Verrerie, pi. xxxiii A. But the great
triumph of ancient genius in this department is the celebrated Port-land
Vase, formerly known as the Barberini Vase, which is now in the British
Museum. It was found in the 16th century at a short distance from Rome, in a
marble coffin within a sepulchral vault, pronounced upon very imperfect
evidence to have been the tomb of Alexander Severus. The extreme beauty of
this urn led Montfaucon and other antiquaries to mistake it for a real
sardonyx. Upon more accurate examination it was ascertained to be composed
of dark blue glass, of a very rich tint, on the surface of which are
delineated in relief elaborately wrought figures of opaque white glass. [See
SCALPTURA] With such
samples before us, we need not wonder that in the time of Nero a pair of
moderate-sized glass cups with handles (
pteroti)
sometimes cost fifty pounds (
HS. sex millibus,
Plin. Nat. 36.195). Another method
practised with success was that of adding coloured glasses in a fused state
to a background, in the manner of enamel. See a medallion with a gryphon,
now in the British Museum (
Catalogue of the Slade Collection,
No. 84).
2. Glass Pastes presenting fac-similes, either in relief or intaglio, of
engraved precious stones. In this way have been preserved exact copies of
many beautiful gems, of which the originals no longer exist, as may be seen
from the catalogues of Stosch, of Tassie, and from similar publications.
These were in demand for the rings of such persons as were not wealthy
enough to purchase real stones, as we perceive from the phrase
“vitreis gemmis ex vulgi anulis” (
Plin. Nat. 35.48). Large medallions also of
this kind are still preserved, and bas-reliefs of considerable magnitude,
which successfully imitate precious materials, and in some cases the true
material has only been ascertained in quite recent years. (See Winckelmann,
1.100.2.27.)
3. Closely allied to the preceding were imitations of coloured precious
stones, such as the carbuncle, the sapphire, the amethyst, and, above all,
the emerald. These counterfeits were executed with such fidelity that
detection was extremely difficult, and great profits were realised by
dishonest dealers who entrapped the unwary (
Plin. Nat. 37.197). That such frauds were practised even upon
the most exalted in station is seen from the anecdote given by Trebellius
Pollio of the whimsical vengeance taken by Gallienus (
Gall.
100.12) on a rogue who had cheated him in this way, and collections are to
be seen at Rome of pieces of coloured glass which were evidently once worn
as jewels, from which they cannot be distinguished by the eye. (
Plin. Nat. 37.98; Senec.
Ep.
90; Isidor.
Orig. 16.15.27; Beckmann,
History of
Inventions, vol. i. p. 199, Eng. Trans. 3rd edit.)
4. One very elegant application of glass deserves to be particularly noticed.
A number of fine stalks of glass of different colours were placed
vertically, and arranged in such a manner as to depict upon the upper
surface some figure or pattern, upon the principle of a minute mosaic. The
filaments thus combined were then subjected to such a degree of heat as
would suffice to soften without melting them, and were thus cemented
together into a solid mass. It is evident that the picture brought out upon
the upper surface would extend down through the whole of the little column
thus formed, and hence, if it was cut into thin slices at right angles to
the direction of the fibres, each of these sections would upon both sides
represent the design which would be multiplied to an extent in proportion to
the total length of the glass threads. Further, if the column is heated and
drawn out, the design becomes proportionately minute. When these sections
have been again fused together side by side, the result is
millefiori glass (
Cat. of the Slade
Collection, pl. iv.). Two beautiful fragments evidently
constructed in this way are accurately commented upon by Winckelmann
(1.100.2, § § 22-24); another, more recently brought from
Egypt, is shown in Wilkinson's work, Pl. xiv., figs. 5, 6, 7; cf. vol. ii.
p. 146. Many mosaic pavements and pictures (
opus
musivum) belong to this head, since the cubes were frequently
composed of opaque glass as well as marble, but these have been already
discussed under
PICTURA pp. 397
f.
5. One method of decoration employed by the ancients consisted in enclosing
designs in gold leaf between two layers of transparent glass. This is most
common from the 3rd century A.D., when small
Christian subjects are thus represented. Examples also occur of a good Greek
period, such as three cups from Canosa, now in the British Museum, perhaps
dating from 200 B.C., but these are very rare. The
Christian examples have been described by Garrucci,
Vetri ornati di
Figure in oro dei Cristiani. In a few rare examples, the gold
leaf has been cut away with a sharp point, in such a way as to produce the
effect of a finely-stippled drawing.
6. Thick sheets of glass of various colours appear to have been laid down for
paving floors, and to have been attached as a lining to the walls and
ceilings of apartments in dwelling-houses, just as scagliola is frequently
employed in Italy, and occasionally in our own country also. Rooms fitted up
in this way were called
vitreae camerae, and
the panels
vitreae quadraturae. Such was the
kind of decoration introduced by Scaurus for the scene of his theatre, not
columns nor pillars of glass as some, nor bas-reliefs as others, have
imagined. (
Plin. Nat. 36.189; Stat.
Syl. 1.5, 42; Senec.
Ep. 76; Vopisc.
Firm. 100.3; Winckelmann, 1.100.2.21; Passeri,
Lucernae Fictiles, p. 67, tab. lxxi.)
7. The question whether glass windows were known to the ancients has, after
much discussion, been set at rest by the excavations at Pompeii, for not
only have many fragments of flat glass been disinterred from time to time,
but in the tepidarium of the public baths a bronze lattice came to light
with some of the panes still inserted in the frame, so as to determine at
once not only their existence, but the mode in which they were secured and
arranged. (Mazois,
Palais de Scaurus, c. viii.
[p. 2.975]p. 97;
Rusines de
Pompéi, vol. iii. p. 77.) A few specimens of window glass
may be seen in the glass collection of the British Museum. [
DOMUS Vol. I. p. 686
b.] The same collection also contains a wooden
picture-frame of late Graeco-Egyptian origin, with a rebate for a sheet of
glass. (Petrie,
Hawara, pl. xii.)
8. From the time that pure glass became known, it must have been remarked
that when darkened upon one side, it possessed the property of reflecting
images. We are certain that an attempt was made by the Sidonians to make
looking-glasses (
Plin. Nat. 36.193), and
equally certain that it must have failed, for the use of metallic mirrors,
which are more costly in the first instance, which require constant care and
attain but imperfectly the end desired, was universal under the Empire.
Respecting ancient mirrors, see
SPECULUM
9. A strange story with regard to an alleged invention of malleable glass is
found in Petronius (100.51), is told still more circumstantially by Dio
Cassius (57.21), and is alluded to by Pliny (
Plin. Nat. 37.195), with an expression of doubt as to its truth.
An artist appeared before Tiberius with a cup of glass. This he dashed
violently upon the ground. When taken up, it was neither broken nor cracked,
but dinted like a piece of metal. The man then produced a mallet, and
hammered it back into its original shape. The emperor inquired whether any
one was acquainted with the secret, and was answered in the negative, upon
which the order was given that he should be instantly beheaded, lest the
precious metals might lose their value, should such a composition become
generally known.
Literature.--Franks in
Art Treasures of the Manchester
Exhibition Section
Vitreous Art; Nesbitt,
Catalogue of the Slade Collection of Glass, Notes on the History
of Glass-making (1871); Blümner,
Technologie, iv. p. 379; Deville,
Hist. de l'Art de la
Verrerie, 1873; Froehner,
La Verrerie antique,
1879; Marquardt and Mommsen,
Handb. d. römischen
Alterthümer, vol. vii. (1886), p. 744. References to
the older literature may be found in the above works.
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